How to sow your perennials
When you open a packet of seed or a bag in which you’ve collected seed from your own garden, it’s tempting to sow them all. But this can result in you losing the lot, as seedlings growing too close are prone to damping off, a fungal disease that can fell your entire batch. Always sow sparingly to give each seedling adequate light and fresh air around its stem and leaves. A healthy atmosphere is vital in raising healthy seedlings. They need a bright spot but mustn’t be exposed to direct sunlight through glass as this can scorch them. Always use proprietary seed compost. It sterile and free from pathogens and weed seeds. Firm the compost surface gently before sowing but aim for the compost ending up no lower than a centimetre below the edge of your tray. Seedlings need light and air which they won’t get if you half fill trays or pots. The best receptacles for seed-sowing are deep half seed trays (around 20cm x 15cm). is Large seed trays tempt you to sow more while pots are too deep in relation to surface area. Sow on the surface of the compost and sprinkle a thin layer of fine grit over the surface. Press down firmly then stand the tray in shallow water until the grit changes colour. Remove the tray and allow to drain. This draws down the seed into intimate contact with the compost. Stand trays in a warm, bright place – indoors near a radiator is ideal. Only water again when the surface is dry. When seedlings are showing true leaves, after the emergence of seed or cotyledon leaves, gently ease them out with a pencil, one at a time and, holding them by the seed leaves – never the stem – space them out in bigger seed trays or give each one an individual cell in a module tray. When seedlings have made a good root system and are growing strongly they can be potted on. Eventually they’ll be big and strong enough to take their place outside.